E85

E85 is an abbreviation for an ethanol fuel blend of up to 85% denatured ethanol fuel and gasoline or other hydrocarbon by volume. E85 is commonly used by flex-fuel vehicles in the United States and Europe. In the United States, government subsidies of ethanol in general and E85 in particular has encouraged a growing infrastructure for retail sale of E85, especially in corn growing states in the Midwest.

E85 allegedly has a number of advantages over conventional gasoline. One claimed advantage is a reduction in tailpipe emissions, if one disregards that E85 increases the emissions of acetaldehyde in vehicles. Another advantage is a high effective octane rating, reducing engine heat and wear, and increasing "performance" -- which is not to be confused with miles per gallon (see below). Because the ethanol component effectively displaces fossil fuels with energy harvested from renewable sources, in theory E85 is less carbon intensive than petroleum. Additionally, there is a greater potential for localized production of ethanol in agricultural areas and using waste materials. Also, a diversification of fuel sources reduces dependence on a particular type of fuel and may increase stability of supply.

Current factory-made E85 vehicles do not deliver as much fuel economy as gasoline vehicles. Some critics of flex-fuel vehicles claim that ethanol can produce as many miles per gallon than gasoline engines, but automotive manufacturers fail to do the things that are necessary to do so. (See Fuel Economy section further down the page)

Corrosion Debate There is vehement debate regarding alleged issues with fuel systems and E85. Allegedly, due to chemical differences between E85 and gasoline, fuel systems and engines not designed or modified to use E85 suffer increased wear and may fail prematurely. However, some researchers come to the opposite conclusion (Footnote 28). GM, for one, has ceased to make any distinction between the two fuels in their fuel components ,beginning in the 2005 model year, concluding that it is a waste of money to incur higher costs in materials for E85-fueled vehicles because E85 does not corrode their fuel systems.

There is no disagreement that some of the environmental and social benefits of ethanol, and therefore E85, are highly dependent on raw materials used to produce the fuel. However, there is great disagreement as to ethanol's role in the pricing and availability of those raw materials.

Food vs. Fuel

Ethanol critics contend that production of ethanol from corn drives up world food prices, causing corn to be unaffordable,or even unavailable at all. Ethanol advocates counter that allegation by pointing out that over 93% of all corn grown in the U.S. is never fed to people, but is instead used as livestock feed. As livestock cannot digest starch efficiently, and dried corn is mostly starch, livestock do not digest much of the starch at all, and it is simply transformed into fecal matter,or manure,not meat, eggs,or milk. U.S.farmers grow more corn every year than people can buy; there is an annual surplus of corn in the U.S (Footnote 29).

Ethanol advocates say that corn prices have increased due to manipulation of the commodities markets and because American corn companies sell more and more U.S.-grown corn to Mexico and China, creating more competition for corn buyers, and driving up its price. E85 critics contend that ethanol producers may not reduce carbon emissions, due to the petroleum and natural gas used in raising corn and refining it. E85 advocates reply by pointing to ethanol producers who do not do so, but instead use E85 or biodiesel fuel to transport E85, and use biomass as a heat source for the distillation of ethanol instead of petro-products like natural gas.

Some say that ethanol produced from waste materials or fast growing non-food crops such as switchgrass is much more beneficial, but not yet economically practical at large scale. Others say that the world can easily replace all of its use of petroleum by simply making ethanol from the many crops that yield more ethanol per acre than corn yields, with existing technology, not future technology (Footnote 26), and that certain elements in the cellulosic ethanol field are more interested in patent rights than in producing the greatest amount of ethanol at the lowest price point.